Preferred diff ratio?

[SideWinderGX]

You need to grind it down in order to get the pinion shims correct, yes. Otherwise you wont be able to install the lsd case because itll bump into the pinion.

Unsure what he used but it wasnt a milling machine, it was a face grinder of some sort.

 

[TurboStreetCar]

How did you set the depth after it was ground down? I would figure it would be easier to install it, measure it, set the depth unmodified then remove the material.

If you remove material first and don't know exactly to the .001" how much was removed, or if it was removed unevenly, then i would assume the depth measurement would be thrown off?

 

[suprarx7nut]

I've run all 3 stock US options in the Mk3. Of the stock ratios I like 3.73 the best by far. In everyday use it's more practical for me. Lower RPMs, more time at full boost before shifting, etc...

For autox you probably want something shorter, like a 3.9-4.3, but otherwise I'd stick with 3.73 or lower.

 

[SideWinderGX]

How did you set the depth after it was ground down? I would figure it would be easier to install it, measure it, set the depth unmodified then remove the material.

If you remove material first and don't know exactly to the .001" how much was removed, or if it was removed unevenly, then i would assume the depth measurement would be thrown off?

Initially, I put on all the shims, measured depth after it was installed and compared it to what it needed to be...did the math and said 'I need x more shims'. After it got ground down, I put x amount of shims on and checked the pattern and it was pretty close. From there I adjusted shims according to what the pattern looked like.

Once its ground down you can't do checking distance so you'll have to do the math beforehand, which will guaranteed get you close anyways.

 

[TurboStreetCar]

Right, that's what I was getting at when I said install it and check first.

I'm going to be looking into this.

 

[rhs]

Got the 3.73 diff in yesterday. I thought it was gonna be a 2 hour job, but turned into 6...typical.

Anyways, this ratio is so much better to drive on the street. 2nd feels like the fastest gear now, rather than 1st, and I don't have to shift every half second.

 

[TurboStreetCar]

Yea 4.30 would be miserable with anything more then 200hp.

 

[eraezer]

Is there any company out there who makes a 3.73? or are there only used ones available?